The mystery of the seabird that barks like a dog

Tânia Pipa from SPEA (BirdLife Portugal) shares news of a very happy discovery on the tiny islet of Baixo off the ‘White Island’ of Graciosa in the Azores.

‘Woof, woof, woof!’ – and so our story begins, back on a sunny June day in 2015 on the tiny Portugeuse islet of Baixo,…with a bark rather than a squawk. Not so surprising you might think, but this bark didn’t come from a dog – it came from a bird! The Bulwer petrel Bulweria bulwerii to be exact, named for the Scottish naturalist James Bulwer who first identified the species while living in Madeira.

Though this little petrel, with its remarkably long wingspan (an impressive 78-90cm for a body length under 30cm), is already known to frequent the Azores islets of Praia and Baixo off the beautiful ‘White Island’ of Graciosa, the distinctive ‘woof, woof, woof’ we heard that day was a very welcome ‘bark’ out of the blue. And for the simple reason that this sound – like the bark of a small dog – is only made by young petrels in the nest. Yet, until then, the only known colony of Bulwer petrel to have a breeding population was on the islet of Vila.

Map of the Azores

We were on Baixo that day to analyse the status of the Monteiro’s Storm-petrel Hydrobates monteiroi as part of SPEA’s work under LIFE EuroSAP – a three year collaborative project across ten countries, launched in 2015 to halt the population decline of sixteen iconic European bird species on a continental scale. Little did we know, we were about to make an unexpected discovery – but there it was, a Bulwer petrel right there on the rocks. However, at the time, we could not completely verify the presence of breeding pairs; although the barking surely endorsed suggestions put forward by researchers at the Portuguese Department of Oceanography and Fisheries (DOF).

Finally, this year, we were able to find more conclusive answers. As part of two new projects – MISTIC SEAS II (a continuation of our work for LIFE EuroSAP) and LuMinAves (to mitigate light pollution affecting seabirds in the Macaronesian archipelagos) – we returned to the islet, determined to solve the mystery of ‘The seabird that barks like a dog’.

Once again, the Monteiro storm-petrels showed us the way. We decided to change strategy and place our mist-net at the site of our first happy ‘accident’ in 2015. Within one hour, we heard a ‘bark’ and spotted our first nest and two birds on the net. We began imitating the call, and over the following nights we found 13 more nests. Upon closer inspection, we found Bulwar petrel eggs – finally confirming their breeding presence on the islet.

Now, we must wait for the chicks to hatch (any day now!) and watch them venture out into the ocean come late September and hopefully returning to the colony with three years. In the meantime, this exciting discovery will hopefully inspire a new impetus to protect a species which is rare in Europe.

Tânia Pipa is responsible for the conservation and management actions of SPEA’s After-LIFE Project on Corvo Island.

With special thanks to the the Natural Park of Graciosa for their support and collaboration, and also the researchers (DOP, Luís Monteiro, Joel Bried and Verónica Neves, amongst others) who have generously shared their expertise in contributing to our greater understanding of the species of the Azores.